1. Field of the Invention
The present invention relates to cleaning compositions and, more particularly, to strong acid-based cleaning compositions. Specifically, the present invention relates to a radiator cleaning composition having a pH value of less than 1.0, yet is nonreactive and nonirritating to human skin tissue.
2. Description of the Prior Art
Numerous compositions and processes have been employed in the past for the purpose of cleaning and removing corrosion products, rust, mineral deposits and scaling, grease, and oil residue from radiators that are used in cooling systems of automobiles, motorcycles, trucks, buses and other vehicles as well as in heavy equipment such as compressors, pumps, turbines and the like. Some of these cleaning processes include, but are not limited to, sand and bead blasting, wire brushing, power washing and muriatic acid cleaning. Other techniques include dipping the radiators in baths containing extremely caustic solutions with pH values greater than 12.5 and, in the great majority of cases, heated to as much as 190.degree. F. Moreover, there are other processes that use ultrasonic cleaning devices in baths of caustic solutions heated from about 145.degree. F. to 175.degree. F.
Examples of acidic compositions which have been utilized for a wide variety of cleaning applications include U.S. Pat. Nos. 4,675,120, 3,514,407, 3,630,933, 4,116,713, 4,181,622, 4,199,469, and 4,250,048. While many of these referenced patents are not specifically designed for cleaning radiators and the like, they do disclose acid-based compositions for the purposes of cleaning a wide variety of different types of surfaces. One unfortunate and significant disadvantage of many of these acid-based cleaning compositions is that while they are effective cleaning agents, they can be extremely corrosive and highly reactive with human skin tissue as well as other compositions having relatively low oxidative states. U.S. Pat. No. 4,477,364 discloses an acidic glass cleaning composition which has a low pH value for cleaning yet is relatively innocuous to skin tissue. However, this particular disclosure is directed to the specific challenges relating to the cleaning of glass surfaces and is so limited thereto.
As mentioned above, prior art bath cleaning techniques include heating the bath to extremely dangerous temperatures. This procedure consumes great amounts of energy and becomes a hazard to use because it can cause both temperature burns and chemical burns. Workers involved in this type of work must wear protective clothing, eye protection, rubber gloves and boots at all times. These processes are also time consuming, do not do an effective cleaning job on heavy corrosion and scaling, and eventually destroy the buildings where they are housed due to the hot and caustic fumes generated by the process.
Once these radiators have been cleaned through any one of these prior art processes, a stage called "rodding" has to be performed. This process consists of a technician lancing each radiator tube with a metal rod to remove any remaining corrosion build-up or sediments from inside the radiator tubes. This procedure is a very time consuming job and involves working very closely with caustic residue left inside the radiator tubes.
As a result of the above, radiator shops have had to deal with expensive fuel consumption, exposure to dangerous, hot caustic solutions, and long working procedures when trying to clean radiators. Nonetheless, this has still not accomplished the desired degree of cleanliness, and bead blasting and wire brushing end up, in many cases, as the only alternative to a truly clean radiator. Consequently, there is still a need for an effective cleaning solution particularly applicable to radiators, such cleaners having requirements different from those of cleaning agents for other types of surfaces and applications. Such a cleaning composition need not be abrasive, and should be effective in removing corrosion products, rust, mineral deposits, scaling, grease and the like, while also being non-corrosive as well as non-reactive with human skin tissue to permit easy and safe use.